Secondary cipher challenge part 5
Here is the fifth part of a six-part challenge. Can you get to the end and crack the final message?
Age
11 to 16
Challenge level
Problem
This is the fifth part of the Secondary Cipher Challenge.
Part 5
katjtjbtiaefbasllepmepnyuefrtqetktjysdeyhfedtrrtbnlkkhjhlqekaspkaeifeqthnjjnujk
tknkthpbtiaefjuebsnjekaefetjphinpbknskthphfbsitksllekkefjkhaelijhvelldhperhfjhlq
tpmtkbtiaefbasllepmepnyuefjtwtjmhtpmkhueeqepyhfedtrrtbnlkxhnytmakasqekh
lhhgniskxiehrbtiaefbslledqtmepefetrxhnasqephkaesfdhrtkuerhfesqtmepefebtiaefa
sjsgexvhfdspdrhfhnfjveasqebahjepkaepsyehrsyskaeysktbsljasiekaegexvhfdkhsbbe
jjbtiaefbasllepmejtwtjjiebtsl
tknkthpbtiaefjuebsnjekaefetjphinpbknskthphfbsitksllekkefjkhaelijhvelldhperhfjhlq
tpmtkbtiaefbasllepmepnyuefjtwtjmhtpmkhueeqepyhfedtrrtbnlkxhnytmakasqekh
lhhgniskxiehrbtiaefbslledqtmepefetrxhnasqephkaesfdhrtkuerhfesqtmepefebtiaefa
sjsgexvhfdspdrhfhnfjveasqebahjepkaepsyehrsyskaeysktbsljasiekaegexvhfdkhsbbe
jjbtiaefbasllepmejtwtjjiebtsl
If you want to work on a computer to solve the problem, you can download this cipher as a text file which doesn't contain any line breaks.
You can use the Cipher Challenge Toolkit to help you decipher it.
Once you've decrypted this message, you should have a keyword.
You can access Part 6 of the Cipher Challenge at http://nrich.maths.org/???
by replacing the ??? with the keyword.